PRODUCTION OF ACID CURING TYPE ORGANIC SELF-CURING SAND

摘要

PURPOSE:To prevent casting defects, to reduce the cost of casting and to improve working environment by adding and mixing an acid curing agent to and with org. binder-coated molding sand formed by adding the org. binder to the molding sand. CONSTITUTION:This process is applied to the acid curing type org. self-curing sand of >=5ml/50g, more preferably 10ml/50g acid consumption. A phenolic resin, modified phenolic resin, furan resin or modified furan resin which cures at a room temp. when mixed together with the acid curing agent is used for the org. binder and such binder is added to the molding sand to coat the molding sand. The acid curing agent prepd. by adding a methanol or ethanol to an aq. soln. of an inorg. acid or arom. sulfonic acid is then added and mixed to and with such molding sand. The cost of casting and casting defects are reduced by producing the molding sand in the above-mentioned manner.